398739787 has 4 divisors (see below), whose sum is σ = 409516576. Its totient is φ = 387963000.

The previous prime is 398739769. The next prime is 398739793. The reversal of 398739787 is 787937893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 787937893 = 3631 ⋅217003.

It is a cyclic number.

It is not a de Polignac number, because 398739787 - 2⁷ = 398739659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398739727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5388339 + ... + 5388412.

It is an arithmetic number, because the mean of its divisors is an integer number (102379144).

Almost surely, 2^398739787 is an apocalyptic number.

398739787 is a gapful number since it is divisible by the number (37) formed by its first and last digit.

398739787 is a deficient number, since it is larger than the sum of its proper divisors (10776789).

398739787 is a wasteful number, since it uses less digits than its factorization.

398739787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10776788.

The product of its digits is 16003008, while the sum is 61.

The square root of 398739787 is about 19968.4698211956. The cubic root of 398739787 is about 736.0317083013.

The spelling of 398739787 in words is "three hundred ninety-eight million, seven hundred thirty-nine thousand, seven hundred eighty-seven".